Looking someone in the eye is a symbol of honesty.
Suo is looking at them.
But since he's looking with one eye, it's not fully.
He is being sincere when he gives advices and compliments to others but when it comes to personal info about himself, he jokes, he lies lies lies.
Eyes are the window to the soul.
Suo isn't showing much of his feelings either. It's hard to read his emotions since he always quickly masks them behind smiles and jokes.
We've only ever seen glimpses of his raw emotions during fights.
So imagine the moment Suo takes off his eye patch is during a scene where he's finally telling something honest about himself.
To people he fully trusts. His friends.
He fully looks at them (Whether with an injured eye or a working one) and let his true, raw emotions show on his face.
